[TowerTalk] Is There a Good Balun...

[Joe Subich, W4TV]

> "back in the days" they also thought connecting one side of the A/C
> to chassis  was a good idea, too.

"Back in the day" it wasn't all that uncommon to get a "bite" from the
microphone - another symptom of common mode RF - particularly when
using a windom with an unbalanced tuner, an elevated vertical, etc.

Low levels of common mode RF may have caused some rough sounding audio
but when the RF voltage on the mic got high enough - the lips were
plenty sensitive to a "high" voltage point on the mic.  Just because
many amateurs did not use effective "baluns" did not mean there wasn't
a need for them ... equipment was not quite as sensitive to the typical
RF voltages created and we did not know to test for that kind of thing.
The transmitter tuned into whatever SWR was present and there was no
thought to the "third wire" in a coaxial cable.  Some antenna makers
even provided a strap to connect one half of the driven element of
their tribander directly to the boom!

Today's solid state equipment gets upset by 3 to 5 volts of RF ... the
old tube gear wasn't phased by 20 or 25 volts.

73,

    ... Joe, W4TV


On 2014-11-26 3:56 PM, Kelly Taylor wrote:
> Not that baluns or chokes are a requirement in every situation, but "back in
> the days" they also thought connecting one side of the A/C to chassis was a
> good idea, too. At least today's Pin 1 problem isn't potentially fatal...
>
> A half-century of research and engineering has changed a lot in electronics
> and science. And, as Jim points out, that some of today's solutions were
> then rendered moot by tubes and tank circuits doesn't mean they don't apply
> today.
>
> The big problem is separating marketing myth from reality. One Mississippi
> manufacturer would have you believe your station will be inoperable without
> every little 'solution' they can dream up, even if they're solutions to
> problems nobody knew existed. Or, in some cases, expensive and ineffective
> solutions to real problems (such as the MaxCon dipole).
>
> There's a lot of snake oil on the market, but that doesn't mean that
> rational solutions, supported by computer modelling and sound reasoning, are
> hooey. Especially if they come from retired engineers with no vested
> interest in whether you read their stuff or not.
>
>
> 73,kelly
> ve4xt
>
>
>
> On 11/26/14 1:39 PM, "Ken" <wa8jxm at gmail.com> wrote:
>
>>
>> On Nov 26, 2014, at 12:48 PM, Wilson <infomet at embarqmail.com> wrote:
>>
>>
>> My own take is that after hearing a lot of talk, much of it BS, and being
>> exposed to a lot of colorful ads, we have developed a ³need² that far
>> overshadows reality.
>
>
> Wilson, I tend to support your view.  ³Back in the
>> days², there was little or no use of baluns.  Look back at my 1960¹s handbooks
>> and antenna books and the mention was rare and certainly not a mainstream
>> requirement.
>
> Ken
>> WA8JXM
>
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